Across
1
Total distance around a shape
6
Distance from center to edge of circle
7
Amount of space an object occupies
8
Rectangle with four equal sides
9
Steepness of a line
10
Repeated addition
Down
1
Number divisible only by 1 and itself
2
Reference line in a graph
3
Single numeral from 0 to 9
4
Three-sided polygon
5
Lines that never intersect
11
Number that divides evenly into another
12
Value that does not change
13
Number greater than zero